Composition for light emitting device and light emitting device containing the same

ABSTRACT

A composition useful for the production of a light emitting device showing suppressed initial degradation, and a light emitting device formed by using the composition are provided. The composition contains a blended host material and a guest material, in which the host material contains an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed, the guest material contains an aromatic amine compound, and the total amount of a silicon atom contained in the host material and a silicon atom contained in the guest material is 20 ppm by mass or less with respect to the total amount of the host material and the guest material.

TECHNICAL FIELD

The present invention relates to a composition for light emitting deviceand a light emitting device containing the same.

BACKGROUND ART

Light emitting devices such as an organic electroluminescent device andthe like can be suitably used for, for example, displays andillumination. As the material used for a light emitting device, forexample, Patent Document 1 proposes a composition containing a compoundH0 and a compound EM1.

PRIOR ART DOCUMENT Patent Document

[Patent Document 1] International Publication WO 2017/170313

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

However, in a light emitting device fabricated using the above-describedcomposition, suppression of initial deterioration was not necessarilysufficient.

Then, the present invention has an object of providing a compositionuseful for producing a light emitting device in which initialdeterioration is suppressed, and a light emitting device formed usingthe composition.

Means for Solving the Problem

The present inventors have intensively studied for solving theabove-described problem, and resultantly found that in a light emittingdevice having an organic layer containing a specific composition, asilicon atom greatly affects the initial deterioration of the lightemitting device, and further found that the initial deterioration of thelight emitting device can be suppressed by setting the amount of asilicon atom in a specific range, leading to completion of the presentinvention. In addition, Patent Document 1 does not disclose that theamount of a silicon atom contained in the composition affects theinitial deterioration of a light emitting device.

That is, the present invention provides the following [1] to [15].

[1] A composition for light emitting device containing a host materialand a guest material blended, wherein

the above-described host material contains an aromatic compound having acondensed ring skeleton in which only three or more benzene rings arecondensed,

the above-described guest material contains an aromatic amine compound,and

the total amount of a silicon atom contained in the above-described hostmaterial and a silicon atom contained in the above-described guestmaterial is 20 ppm by mass or less with respect to the total amount ofthe above-described host material and the above-described guestmaterial.

[2] The composition for light emitting device according to [1], whereinthe above-described aromatic compound is a compound represented by theformula (FH):

[wherein,

n^(1H) represents an integer of 0 or more.

Ar^(1H) represents a group obtained by removing from an aromatichydrocarbon having a condensed ring skeleton in which only three or morebenzene rings are condensed n^(1H) or more hydrogen atoms bondingdirectly to carbon atoms constituting the condensed ring skeleton, andthis group optionally has a substituent. When a plurality of thesubstituents are present, they may be the same or different and may becombined together to form a ring together with atoms to which they areattached.

R^(1H) represents an aryl group or a monovalent heterocyclic group, andthe foregoing groups optionally have a substituent. When a plurality ofthe substituents are present, they may be the same or different and maybe combined together to form a ring together with atoms to which theyare attached. When a plurality of RIF′ are present, they may be the sameor different and may be combined together to form a ring together withatoms to which they are attached.].

[3] The composition for light emitting device according to [1] or [2],wherein the above-described condensed ring skeleton is a condensed ringskeleton in which only 3 or more and 5 or less benzene rings arecondensed.

[4] The composition for light emitting device according to [3], whereinthe above-described condensed ring skeleton is an anthracene skeleton, aphenanthrene skeleton, a benzoanthracene skeleton, a benzophenanthreneskeleton or a pyrene skeleton.

[5] The composition for light emitting device according to any one of[1] to [4], wherein the above-described aromatic amine compound is acompound represented by the formula (FB):

[wherein,

n^(1B) represents an integer of 1 or more.

Ar^(1B) represents an aromatic hydrocarbon group or an aromaticheterocyclic group, and the foregoing groups optionally have asubstituent. When a plurality of the substituents are present, they maybe the same or different and may be combined together to form a ringtogether with atoms to which they are attached.

R^(1B) represents an amino group or a substituted amino group, and theforegoing groups optionally have a substituent. When a plurality of thesubstituents are present, they may be the same or different and may becombined together to form a ring together with atoms to which they areattached. When a plurality of R^(1B) are present, they may be the sameor different and may be combined together to form a ring together withatoms to which they are attached.].

[6] The composition for light emitting device according to any one of[1] to [5], further comprising at least one selected from groupconsisting of a hole transporting material, a hole injection material,an electron transporting material, an electron injection material, alight emitting material, an antioxidant and a solvent.

[7] A light emitting device having an anode, a cathode, and an organiclayer disposed between the above-described anode and the above-describedcathode, wherein the above-described organic layer is a layer containingthe composition for light emitting device according to any one of [1] to[6].

[8] A method of producing a composition for light emitting devicecontaining a host material and a guest material blended, including

a host material preparation step of preparing a host material containingan aromatic compound having a condensed ring skeleton in which onlythree or more benzene rings are condensed,

a guest material preparation step of preparing a guest materialcontaining an aromatic amine compound, and

a production step of mixing the above-described host material and theabove-described guest material at a compounding ratio by which the totalamount of a silicon atom contained in the above-described host materialand a silicon atom contained in the above-described guest material is 20ppm by mass or less, to obtain a composition for light emitting device.

[9] The production method according to [8], wherein the above-describedguest material preparation step includes

a preparation step (B-1) of preparing the above-described aromatic aminecompound containing a silicon atom mixed therein, and

a step (B-2) of purifying at least a part of the above-describedaromatic amine compound prepared in the above-described step (B-1) toremove at least a part of the above-described silicon atom.

[10] The production method according to [8] or [9], wherein theabove-described host material preparation step includes

a step (A-1) of preparing the above-described aromatic compoundcontaining a silicon atom mixed therein, and

a step (A-2) of purifying at least a part of the above-describedaromatic compound prepared in the above-described step (A-1) to removeat least a part of the above-described silicon compound.

[11] A method of producing a composition for light emitting devicecontaining a host material and a guest material blended, including

a host material preparation step of preparing a host material containingan aromatic compound having a condensed ring skeleton in which onlythree or more benzene rings are condensed,

a determination step of determining the compounding ratio of theabove-described guest material with respect to the above-described hostmaterial,

a guest material preparation step of preparing a guest materialcontaining an aromatic amine compound and in which, when mixed with theabove-described host material at the above-described compounding ratio,the total amount of a silicon atom contained in the above-described hostmaterial and a silicon atom contained in the above-described guestmaterial with respect to the total amount of the above-described hostmaterial and the above-described guest material is 20 ppm by mass orless, and

a production step of mixing the above-described host material and theabove-described guest material at the above-described compounding ratio,to obtain a composition for light emitting device.

[12] A method of producing a composition for light emitting devicecontaining a host material and a guest material blended, including

a guest material preparation step of preparing a guest materialcontaining an aromatic amine compound,

a determination step of determining the compounding ratio of theabove-described host material with respect to the above-described guestmaterial,

a host material preparation step of preparing a host material containingan aromatic compound having a condensed ring skeleton in which onlythree or more benzene rings are condensed and in which, when mixed withthe above-described guest material at the above-described compoundingratio, the total amount of a silicon atom contained in theabove-described host material and a silicon atom contained in theabove-described guest material with respect to the total amount of theabove-described host material and the above-described guest material is20 ppm by mass or less, and a production step of mixing theabove-described guest material and the above-described host material atthe above-described compounding ratio, to obtain a composition for lightemitting device.

[13] A method of producing a composition for light emitting devicecontaining a host material and a guest material blended, including

a host material preparation step of preparing an aromatic compoundhaving a condensed ring skeleton in which only three or more benzenerings are condensed as the host material,

a guest material preparation step of preparing an aromatic aminecompound as the guest material,

a determination step of determining the compounding ratio of theabove-described host material and the above-described guest material,

a purification step of purifying at least a part of the above-describedaromatic compound and the above-described aromatic amine compound sothat, when the above-described host material and the above-describedguest material are mixed at the above-described compounding ratio, thetotal amount of a silicon atom contained in the above-described hostmaterial and a silicon atom contained in the above-described guestmaterial with respect to the total amount of the above-described hostmaterial and the above-described guest material is 20 ppm by mass orless, and

a production step of mixing the above-described host material containingthe above-described aromatic compound and the above-described guestmaterial containing the above-described aromatic amine compound at theabove-described compounding ratio, to obtain a composition for lightemitting device.

[14] The production method according to any one of [8] to [13], furtherincluding

a host material measurement step of measuring the content of a siliconatom contained in the above-described aromatic compound, and

a gust material measurement step of measuring the content of a siliconatom contained in the above-described aromatic amine compound.

[15] A method of producing a light emitting device containing an anode,a cathode and an organic layer disposed between the above-describedanode and the above-described cathode, comprising

a step of forming the above-described organic layer from a compositionfor light emitting device produced by the production method according toany one of [8] to [14].

Effect of the Invention

According to this invention, a composition which is useful forproduction of a light emitting device in which the initial deteriorationis suppressed can be provided. Further, according to the presentinvention, a light emitting device containing the above-describedcomposition can be provided. Further, according to the presentinvention, a method for producing the above-described composition andthe above-described light emitting device can be provided.

MODES FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present embodiment will bedescribed in detail.

Explanation of Common Terms

Terms commonly used in the present specification have the followingmeanings unless otherwise stated.

“Room temperature” denotes 25° C.

Me represents a methyl group, Et represents an ethyl group, Burepresents a butyl group, i-Pr represents an isopropyl group and t-Burepresents a tert-butyl group.

The hydrogen atom may be a heavy hydrogen atom or a light hydrogen atom.

“Polymer compound” denotes a polymer having molecular weightdistribution and having a polystyrene-equivalent number-averagemolecular weight of 1×10³ to 1×10⁸.

“Low molecular compound” denotes a compound having no molecular weightdistribution and having a molecular weight of 1×10⁴ or less.

“Constitutional unit” denotes a unit occurring once or more times in thepolymer compound.

“Alkyl group” may be any of linear and branched. The number of carbonatoms of the linear alkyl group, not including the number of carbonatoms of the substituent, is usually 1 to 50, preferably 1 to 20, andmore preferably 1 to 10. The number of carbon atoms of the branchedalkyl group, not including the number of carbon atoms of thesubstituent, is usually 3 to 50, preferably 3 to 20, and more preferably4 to 10. The alkyl group optionally has a substituent and examplesthereof include, for example, a methyl group, an ethyl group, anisopropyl group, a butyl group, an isobutyl group, a tert-butyl group, apentyl group, a hexyl group, a heptyl group, an octyl group, a2-ethylhexyl group, a decyl group, a 3,7-dimethyloctyl group, a2-ethyloctyl group, a dodecyl group, a trifluoromethyl group, a3-phenylpropyl group, a 3-(4-methylphenyl)propyl group, a3-(3,5-di-hexylphenyl)propyl group and a 6-ethyloxyhexyl group.

The number of carbon atoms of “cycloalkyl group”, not including thenumber of carbon atoms of the substituent, is usually 3 to 50, andpreferably 4 to 10. The cycloalkyl group optionally has a substituentand examples thereof include a cyclohexyl group and a methylcyclohexylgroup.

The number of carbon atoms of “alkylene group”, not including the numberof carbon atoms of the substituent, is usually 1 or more and 20 or less,preferably 1 or more and 15 or less, and more preferably 1 or more and10 or less. The alkylene group optionally has a substituent and examplesthereof include a methylene group, an ethylene group, a propylene group,a butylene group, a hexylene group and an octylene group.

The number of carbon atoms of “cycloalkylene group”, not including thenumber of carbon atoms of the substituent, is usually 3 or more and 20or less. The cycloalkylene group optionally has a substituent andexamples thereof include a cyclohexylene group.

“Aromatic hydrocarbon group” denotes a group obtained by removing froman aromatic hydrocarbon one or more hydrogen atoms bonding directly tocarbon atoms constituting the ring. A group obtained by removing from anaromatic hydrocarbon one hydrogen atom bonding directly to a carbon atomconstituting the ring is referred to also as “aryl group”. A groupobtained by removing from an aromatic hydrocarbon two hydrogen atomsbonding directly to carbon atoms constituting the ring is referred toalso as “arylene group”.

The number of carbon atoms of the aromatic hydrocarbon group, notincluding the number of carbon atoms of the substituent, is usually 6 to60, preferably 6 to 30, and more preferably 6 to 18.

“Aromatic hydrocarbon group” includes, for example, groups obtained byremoving from mono-cyclic aromatic hydrocarbons (including, for example,benzene) or poly-cyclic aromatic hydrocarbons (including, for example,bi-cyclic aromatic hydrocarbons such as naphthalene, indene and thelike; tri-cyclic aromatic hydrocarbons such as anthracene, phenanthrene,dihydrophenanthrene, fluorene and the like; tetra-cyclic aromatichydrocarbons such as benzoanthracene, benzophenanthrene, benzofluorene,pyrene, fluoranthene and the like; penta-cyclic aromatic hydrocarbonssuch as dibenzoanthracene, dibenzophenanthrene, dibenzofluorene,perylene, benzofluoranthene and the like; hexa-cyclic aromatichydrocarbons such as spirobifluorene and the like; and hepta-cyclicaromatic hydrocarbons such as benzospirobifluorene,acenaphthofluoranthene and the like) one or more hydrogen atoms bondingdirectly to carbon atoms constituting the ring, and the foregoing groupsoptionally have a substituent. The aromatic hydrocarbon group includesgroups obtained by bonding a plurality of these groups.

“Alkoxy group” may be any of linear and branched. The number of carbonatoms of the linear alkoxy group, not including the number of carbonatoms of the substituent, is usually 1 to 40, and preferably 1 to 10.The number of carbon atoms of the branched alkoxy group, not includingthe number of carbon atoms of the substituent, is usually 3 to 40, andpreferably 4 to 10. The alkoxy group optionally has a substituent andincludes, for example, a methoxy group, an ethoxy group, an isopropyloxygroup, a butyloxy group, a hexyloxy group, a 2-ethylhexyloxy group,3,7-dimethyloctyloxy group and a lauryloxy group.

The number of carbon atoms of “cycloalkoxy group”, not including thenumber of carbon atoms of the substituent, is usually 3 to 40, andpreferably 4 to 10. The cycloalkoxy group optionally has a substituentand includes, for example, a cyclohexyloxyl group.

The number of carbon atoms of “aryloxy group”, not including the numberof carbon atoms of the substituent, is usually 6 to 60, and preferably 6to 48. The aryloxy group optionally has a substituent and includes, forexample, a phenoxy group, a naphthyloxy group, an anthracenyloxyl groupand a pyrenyloxy group.

“Heterocyclic group” denotes a group obtained by removing from aheterocyclic compound one or more hydrogen atoms bonding directly tocarbon atoms or hetero atoms constituting the ring. Of heterocyclicgroups, preferable is “aromatic heterocyclic group” which is a groupobtained by removing from an aromatic heterocyclic compound one or morehydrogen atoms bonding directly to carbon atoms or hetero atomsconstituting the ring. A group obtained by removing from a heterocycliccompound p hydrogen atoms bonding directly to carbon atoms or heteroatoms constituting the ring (p represents an integer of 1 or more.) isalso referred to as “p-valent heterocyclic group”. A group obtained byremoving from an aromatic heterocyclic compound p hydrogen atoms bondingdirectly to carbon atoms or hetero atoms constituting the ring is alsoreferred to as “p-valent aromatic heterocyclic group”.

“Aromatic heterocyclic compound” includes, for example, compounds inwhich the heterocyclic ring itself shows aromaticity such as azole,thiophene, furan, pyridine, diazabenzene, triazine, azanaphthalene,diazanaphthalene, carbazole and the like, and compounds in which anaromatic ring is condensed to a heterocyclic ring even if theheterocyclic ring itself shows no aromaticity such as phenoxazine,phenothiazine, benzopyran and the like.

The number of carbon atoms of the heterocyclic group, not including thenumber of carbon atoms of the substituent, is usually 1 to 60,preferably 2 to 40, and more preferably 3 to 20. The number of thehetero atom of the heterocyclic group, not including the number ofcarbon atoms of the substituent, is usually 1 to 30, preferably 1 to 10,and more preferably 1 to 3.

The heterocyclic group optionally has a substituent and includes, forexample, groups obtained by removing from a mono-cyclic heterocycliccompound (including, for example, furan, thiophene, oxadiazole, pyrrole,diazole, triazole, tetrazole, pyridine, diazabenzene and triazine) or apoly-cyclic heterocyclic compound (including, for example, bi-cyclicheterocyclic compounds such as azanaphthalene, diazanaphthalene,benzofuran, benzothiophene, indole, benzodiazole, benzothiadiazole andthe like; tri-cyclic heterocyclic compounds such as dibenzofuran,dibenzothiophene, dibenzoborole, dibenzosilole, dibenzophosphole,dibenzoselenophene, carbazole, azacarbazole, diazacarbazole,phenoxazine, phenothiazine, 9,10-dihydroacridine, 5,10-dihydrophenazine,phenazaborine, phenophosphazine, phenoselenazine, phenazacillin,azaanthracene, diazaanthracene, azaphenanthrene, diazaphenanthrene andthe like; tetra-cyclic heterocyclic compounds such ashexaazatriphenylene, benzocarbazole, benzonaphthofuran,benzonaphthothiophene and the like; penta-cyclic heterocyclic compoundssuch as dibenzocarbazole, indolocarbazole, indenocarbazole and the like;hexa-cyclic heterocyclic compounds such as carbazolocarbazole,benzoindrocarbazole, benzoindenocarbazole and the like; and hepta-cyclicheterocyclic compounds such as dibenzoindrocarbazole and the like) oneor more hydrogen atoms bonding directly to atoms constituting the ring,and the foregoing groups optionally have a substituent. The heterocyclicgroup includes groups obtained by bonding a plurality of these groups.

“Halogen atom” denotes a fluorine atom, a chlorine atom, a bromine atomor an iodine atom.

“Amino group” optionally has a substituent, and substituted amino groups(namely, secondary amino groups or tertiary amino groups, preferably,tertiary amino groups) are preferred. As the substituent which an aminogroup has, an alkyl group, a cycloalkyl group, an aryl group or amonovalent heterocyclic group is preferable. When a plurality of thesubstituents which an amino group has are present, they may be the sameor different and may be combined together to form a ring together withnitrogen atoms to which they are attached.

The substituted amino group includes, for example, a dialkylamino group,a dicycloalkylamino group and a diarylamino group.

The amino group includes, for example, a dimethylamino group, adiethylamino group, a diphenylamino group, a bis(methylphenyl)aminogroup and a bis(3,5-di-tert-butylphenyl)amino group.

“Alkenyl group” may be any of linear and branched. The number of carbonatoms of the linear alkenyl group, not including the number of carbonatoms of the substituent, is usually 2 to 30, and preferably 3 to 20.The number of carbon atoms of the branched alkenyl group, not includingthe number of carbon atoms of the substituent, is usually 3 to 30, andpreferably 4 to 20.

The number of carbon atoms of the “cycloalkenyl group”, not includingthe number of carbon atoms of the substituent, is usually 3 to 30, andpreferably 4 to 20.

The alkenyl group and the cycloalkenyl group optionally have asubstituent and examples thereof include a vinyl group, a 1-propenylgroup, a 2-propenyl group, a 2-butenyl group, a 3-butenyl group, a3-pentenyl group, a 4-pentenyl group, a 1-hexenyl group, a 5-hexenylgroup and a 7-octenyl group, and these groups having a substituent.

“Alkynyl group” may be any of linear and branched. The number of carbonatoms of the alkynyl group, not including the number of carbon atoms ofthe substituent, is usually 2 to 20, and preferably 3 to 20. The numberof carbon atoms of the branched alkynyl group, not including the numberof carbon atoms of the substituent, is usually 4 to 30, and preferably 4to 20.

The number of carbon atoms of the “cycloalkynyl group”, not includingthe number of carbon atoms of the substituent, is usually 4 to 30, andpreferably 4 to 20.

The alkynyl group and the cycloalkynyl group optionally have asubstituent and examples thereof include an ethynyl group, a propynylgroup, a butynyl group, a pentynyl group, a hexynyl group and a5-hexynyl group, and these groups having a substituent.

“Crosslinkable group” refers to a group capable of generating a new bondby being subjected to a heating treatment, an ultraviolet irradiationtreatment, a near-ultraviolet irradiation treatment, a visible lightirradiation treatment, an infrared irradiation treatment, a radicalreaction and the like, and is preferably a group represented by any ofthe formula (B-1) to the formula (B-17). The foregoing groups optionallyhave a substituent.

“Substituent” includes, for example, a halogen atom, a cyano group, analkyl group, a cycloalkyl group, an aryl group, a monovalentheterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxygroup, an amino group, a substituted amino group, an alkenyl group, acycloalkenyl group, an alkynyl group and a cycloalkynyl group. Thesubstituent may be a crosslinkable group. When a plurality ofsubstituents are present, they may be combined together to form a ringtogether with atoms to which they are attached, however, it ispreferable that they do not form a ring.

“Amount of silicon atom” can be measured by an ICP emissionspectroscopic analysis method (inductively coupled plasma emissionspectrometry). That is, “amount of silicon atom” denotes the massconcentration of a silicon atom as measured by an ICP emissionspectroscopic analysis method. Further, when “amount of silicon atom” is“0 ppm by mass”, it means that the mass concentration of a silicon atomis below the detection limit when measured by an ICP emissionspectroscopic analysis method.

In the composition for light emitting device of the present embodiment,the host material means a material that physically, chemically orelectrically interacts with the guest material. By this interaction, forexample, it becomes possible to improve or adjust the light emissioncharacteristics, charge transport characteristics or charge injectioncharacteristics of the composition for light emitting device of thepresent embodiment.

In the composition for light emitting device of the present embodiment,when explained taking a light emitting material as an example, the hostmaterial and the guest material electrically interact with each otherand electric energy is transferred efficiently from the host material tothe guest material, so that the guest material can emit light moreefficiently.

<Host Material>

The host material contains an aromatic compound having a condensed ringskeleton in which only three or more benzene rings are condensed. Thearomatic compound having a condensed ring skeleton in which only threeor more benzene rings are condensed may contain only one type of thecondensed ring skeleton in which only three or more benzene rings arecondensed, or may contain two or more types of the condensed ringskeletons. Further, the aromatic compound having a condensed ringskeleton in which only three or more benzene rings are condensed maycontain only one type of the condensed ring skeleton in which only threeor more benzene rings are condensed, or two or more types of thecondensed ring skeletons, in the compound. Hereinafter, the aromaticcompound having a condensed ring skeleton in which only three or morebenzene rings are condensed contained in the host material may bereferred to as “aromatic compound for host material” in some cases.

In the condensed ring skeleton of the aromatic compound for hostmaterial, the number of condensed benzene rings is usually 3 to 10, andsince the initial deterioration of the light emitting device of thepresent embodiment is more suppressed, it is preferably 3 to 7, morepreferably 3 to 5, and even more preferably 3 or 4.

The condensed ring skeleton of the aromatic compound for host materialcan be said to be a carbon skeleton of a condensed ring in which onlythree or more benzene rings are condensed. The condensed ring skeletonis preferably an anthracene skeleton, a phenanthrene skeleton, abenzoanthracene skeleton, a benzophenanthrene skeleton or a pyreneskeleton, more preferably an anthracene skeleton, benzoanthraceneskeleton or a pyrene skeleton, and further preferably an anthraceneskeleton, because the initial deterioration of the light emitting deviceof the present embodiment is more suppressed.

The aromatic compound for host material may be an aromatic hydrocarbonhaving a condensed ring skeleton in which only three or more benzenerings are condensed (hereinafter, also referred to as “condensedring-containing aromatic hydrocarbon”), and the aromatic hydrocarbonoptionally has a substituent. The substituent which the condensedring-containing aromatic hydrocarbon optionally has is preferably ahalogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, acycloalkoxy group, an aryl group, a monovalent heterocyclic group or asubstituted amino group, more preferably an alkyl group, cycloalkylgroup, an aryl group or a monovalent heterocyclic group, furtherpreferably an aryl group or a monovalent heterocyclic group,particularly preferably an aryl group, and the foregoing groupsoptionally further have a substituent.

In the substituent which the condensed ring-containing aromatichydrocarbon optionally has, the aryl group is preferably a groupobtained by removing from a monocyclic or bicyclic to hexa-cyclicaromatic hydrocarbon one or more hydrogen atoms bonding directly tocarbon atoms constituting the ring, more preferably a group obtained byremoving from a monocyclic or bicyclic to tetracyclic aromatichydrocarbon one or more hydrogen atoms bonding directly to carbon atomsconstituting the ring, further preferably a group obtained by removingfrom benzene, naphthalene, dihydrophenanthrene, fluorene orbenzofluorene one or more hydrogen atoms bonding directly to carbonatoms constituting the ring, and particularly preferably a phenyl groupor a naphthyl group, and the foregoing groups optionally have asubstituent.

In the substituent which the condensed ring-containing aromatichydrocarbon optionally has, the monovalent heterocyclic group ispreferably a group obtained by removing from a monocyclic or bicyclic tohexa-cyclic heterocyclic compound one or more hydrogen atoms bondingdirectly to atoms constituting the ring, more preferably a groupobtained by removing from a monocyclic or bicyclic to tetracyclicheterocyclic compound one or more hydrogen atoms bonding directly toatoms constituting the ring, further preferably a group obtained byremoving from pyridine, diazabenzene, triazine, azanaphthalene,diazanaphthalene, dibenzofuran, dibenzothiophene, carbazole,benzocarbazole, banzonaphthofuran or benzonaphthothiophene one or morehydrogen atoms bonding directly to atoms constituting the ring, and theforegoing groups optionally have a substituent.

In the substituted amino group as the substituent which the condensedring-containing aromatic hydrocarbon optionally has, the substituent ofthe amino group is preferably an aryl group or a monovalent heterocyclicgroup, more preferably an aryl group, and the foregoing groupsoptionally further have a substituent. The examples and preferableranges of the aryl group which is the substituent of the amino group arethe same as the examples and preferable ranges of the aryl group as thesubstituent which the condensed ring-containing aromatic hydrocarbonoptionally has. The examples and preferable ranges of the monovalentheterocyclic group which is the substituent of the amino group are thesame as the examples and preferable ranges of the monovalentheterocyclic group as the substituent which the condensedring-containing aromatic hydrocarbon optionally has.

The condensed ring-containing aromatic hydrocarbon preferably has asubstituent since the initial deterioration of the light emitting deviceof the present embodiment is more suppressed. When the condensedring-containing aromatic hydrocarbon has a substituent, the total numberof the substituents which the condensed ring-containing aromatichydrocarbon has usually 1 to 20 (providing it is not higher than thetotal number of hydrogen atoms which the condensed ring-containingaromatic hydrocarbon has, the same shall apply hereinafter), and sincesynthesis of the host material is easy, the number is preferably 1 to15, more preferably 1 to 10, further preferably from 1 to 7,particularly preferably from 1 to 5, and especially preferably from 1 to3.

The substituent which the substituent which the condensedring-containing aromatic hydrocarbon optionally has optionally furtherhas is preferably a halogen atom, an alkyl group, a cycloalkyl group, analkoxy group, a cycloalkoxy group, an aryl group, a monovalentheterocyclic group or a substituted amino group, more preferably analkyl group, a cycloalkyl group, an aryl group, a monovalentheterocyclic group or a substituted amino group, and further preferablyan alkyl group or a cycloalkyl group, and the foregoing groupsoptionally further have a substituent, however, it is preferable thatthey do not have a substituent.

The examples and preferable ranges of the aryl group, the monovalentheterocyclic group and the substituted amino group as the substituentwhich the substituent which the condensed ring-containing aromatichydrocarbon optionally has optionally further has are the same as theexamples and the preferable range of the aryl group, the monovalentheterocyclic group and the substituted amino group as the substituentwhich the ring-containing aromatic hydrocarbon optionally has,respectively.

The host material may further contain a compound other than the aromaticcompound for host material, however, since the initial deterioration ofthe light emitting device of the present embodiment is more suppressed,it is preferable that the aromatic compound for host material iscontained as the main component. The content ratio of the aromaticcompound for host material in the host material may be, for example, 10%by mass or more, and since the initial deterioration of the lightemitting device of the present embodiment is more suppressed, it ispreferably 30% by mass or more, more preferably 50% by mass or more,further preferably 70% by mass or more, particularly preferably 90% bymass or more, and especially preferably 95% by mass or more, and mayalso be 100% by mass.

The host material may contain only one type of the aromatic compound forhost material, or may contain two or more types of the aromaticcompounds for host material. When the host material further contains acompound other than the aromatic compound for host material, the hostmaterial may contain only one type of the compound other than thearomatic compound for host material, or may contain two or more types ofthe compounds other than the aromatic compound for host material.

The aromatic compound for host material may be a polymer compound(hereinafter, referred to also as “polymer host material”) or may be alow molecular compound (hereinafter, referred to also as “low molecularhost material”), and the low molecular host material is preferred.

(Low Molecular Host Material)

The molecular weight of the low molecular host material is usually 1×10²to 1×10⁴, preferably 2×10² to 5×10³, more preferably 3×10² to 2×10³, andfurther preferably 4×10² to 1×10³.

The total number of condensed ring skeletons in which only three or morebenzene rings are condensed contained in the low molecular host materialis usually 1 to 10, and since the initial degradation of the lightemitting device of the present embodiment is more suppressed, it ispreferably 1 to 7, more preferably 1 to 5, further preferably 1 to 3,and particularly preferably 1.

The low molecular host material may contain only one type of thecondensed ring skeleton in which only three or more benzene rings arecondensed or may contain 2 or more types of the skeletons, and sincesynthesis of the low molecular host material is easy, it containspreferably 1 to 5 types of the skeletons, more preferably 1 to 3 typesof the skeletons, and further preferably 1 type of the skeleton.

It is preferable that the low molecular host material contains acondensed ring skeleton in which only three or more benzene rings arecondensed as a group obtained by removing from an aromatic hydrocarbonhaving a condensed ring skeleton in which only three or more benzenerings are condensed one or more hydrogen atoms bonding directly tocarbon atoms constituting the condensed ring skeleton (hereinafter,referred to also as “condensed ring-containing aromatic hydrocarbongroup”), since the initial degradation of the light emitting device ofthe present embodiment is more suppressed, and this group optionally hasa substituent.

The total number of the condensed ring-containing aromatic hydrocarbongroup contained in the low molecular host material is usually 1 to 10,and since the initial degradation of the light emitting device of thepresent embodiment is more suppressed, it is preferably 1 to 7, morepreferably 1 to 5, further preferably 1 to 3, and particularlypreferably 1.

The low molecular host material may contain only one type of thecondensed ring-containing aromatic hydrocarbon group, or may contain twoor more types, and since synthesis of the low molecular host material iseasy, it may contain preferably 1 to 5 types of the groups, morepreferably 1 to 3 types of the groups, and further preferably 1 type ofthe group.

In the low molecular host material, the examples and preferable rangesof the substituent which the condensed ring-containing aromatichydrocarbon group optionally has are the same as the examples andpreferable ranges of the substituent which the condensed ring-containingaromatic hydrocarbon optionally has.

[Compound Represented by the Formula (FH)]

The low molecular host material is preferably a compound represented bythe formula (FH), since the initial degradation of the light emittingdevice of the present embodiment is more suppressed.

n^(1H) is usually an integer of 10 or less, and since synthesis of thecompound represented by the formula (FH) is easy, it is preferably aninteger of 7 or less, more preferably an integer of 5 or less, andfurther preferably an integer of 3 or less. Further, n^(1H) ispreferably an integer of 1 or more, since the initial deterioration ofthe light emitting device of this embodiment is more suppressed.

In Arm, the substituent that the condensed ring-containing aromatichydrocarbon group optionally has is a substituent other than an arylgroup and a monovalent heterocyclic group, and is preferably a halogenatom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxygroup or a substituted amino group, more preferably an alkyl group or acycloalkyl group, and the foregoing groups optionally further have asubstituent.

The examples and preferable ranges of the substituted amino group as thesubstituent which the condensed ring-containing aromatic hydrocarbongroup optionally has are the same as the examples and preferable rangeof the substituted amino group as the substituent which the condensedring-containing aromatic hydrocarbon optionally has.

The examples and preferable ranges of the substituent which thesubstituent which the condensed ring-containing aromatic hydrocarbongroup optionally has optionally further has are the same as the examplesand preferable ranges of the substituent which the substituent which thecondensed ring-containing aromatic hydrocarbon optionally has optionallyfurther has.

R^(1H) is preferably an aryl group optionally having a substituent,since the initial deterioration of the light emitting device of thisembodiment is more suppressed.

The examples and preferable ranges of the aryl group and the monovalentheterocyclic group for R^(1H) are the same as the examples andpreferable range of the aryl group and the monovalent heterocyclic groupas the substituent which the condensed ring-containing aromatichydrocarbon optionally has, respectively.

The examples and preferable ranges of the substituent which R^(1H)optionally has are the same as the examples and preferable ranges of thesubstituent which the substituent which the condensed ring-containingaromatic hydrocarbon optionally has optionally further has.

Examples of the low molecular host material include compoundsrepresented by the following formulas and compounds described inExamples. These compounds optionally have a substituent. In the formula,Z¹ represents an oxygen atom or a sulfur atom. When a plurality of Z′are present, they may be the same or different.

(Polymer Host Material)

The polymer host material has a polystyrene-equivalent number-averagemolecular weight of preferably 5×10³ to 1×10⁶, more preferably 1×10⁴ to5×10⁵, and further preferably 2×10⁴ to 2×10⁵. The polymer host materialhas a polystyrene-equivalent weight-average molecular weight ofpreferably 1×10⁴ to 2×10⁶, more preferably 2×10⁴ to 1×10⁶, and furtherpreferably 5×10⁴ to 5×10⁵.

The polymer host material may be any of a block copolymer, a randomcopolymer, an alternative copolymer and a graft copolymer, and may alsobe another form, and it is preferably a copolymer obtained bycopolymerizing a plurality of raw material monomers.

It is preferable that the polymer host material contains a condensedring skeleton in which only three or more benzene rings are condensed asa group obtained by removing from an aromatic hydrocarbon having acondensed ring skeleton in which only three or more benzene rings arecondensed one or more hydrogen atoms bonding directly to carbon atomsconstituting the condensed ring skeleton (the condensed ring-containingaromatic hydrocarbon group), and this group optionally has asubstituent.

The polymer host material preferably contains a condensedring-containing aromatic hydrocarbon group in the main chain of thepolymer compound, more preferably contains a group obtained by removingfrom an aromatic hydrocarbon having a condensed ring skeleton in whichonly three or more benzene rings are condensed two hydrogen atomsbonding directly to carbon atoms constituting the condensed ringskeleton (divalent condensed ring-containing aromatic hydrocarbon group)in the main chain of the polymer compound, since the initial degradationof the light emitting device of the present embodiment is moresuppressed. This group optionally has a substituent.

In the polymer host material, the condensed ring-containing aromatichydrocarbon group is preferably a group obtained by removing from acompound represented by the formula (FH) one or more (preferably 5 orless, more preferably 1 to 3, and further preferably 2) hydrogen atoms,since the initial degradation of the light emitting device of thepresent embodiment is more suppressed.

In the polymer host material, the content of the condensedring-containing aromatic hydrocarbon group contained in the polymercompound is usually 0.1% by mol to 100% by mol with respect to the totalcontent of all constitutional units contained in the polymer compound,and since the initial degradation of the light emitting device of thepresent embodiment is more suppressed, it is preferably 1% by mol to100% by mol, more preferably 10% by mol to 100% by mol, and furtherpreferably 30% by mol to 100% by mol.

The polymer host material may contain only one type of the condensedring-containing aromatic hydrocarbon group, and may contain two or moretypes, and since synthesis of the polymer host material is easy, it maycontain preferably 1 to 5 types of the groups, more preferably 1 to 3types of the groups, and further preferably 1 type of the group.

In the polymer host material, the examples and preferable ranges of thesubstituent which the condensed ring-containing aromatic hydrocarbongroup optionally has are the same as the examples and preferable rangesof the substituent which the condensed ring-containing aromatichydrocarbon optionally has.

The polymer host material may contain a constitutional unit other thanthe condensed ring-containing aromatic hydrocarbon group in the polymercompound, preferably contains a constitutional unit other than thecondensed ring-containing aromatic hydrocarbon group in the polymercompound.

The constitutional unit other than the condensed ring-containingaromatic hydrocarbon group includes, for example, groups obtained byremoving from an aromatic hydrocarbon group (preferably an arylenegroup), a heterocyclic group (preferably a divalent heterocyclic group)and an aromatic amine compound other than the condensed ring-containingaromatic hydrocarbon group one or more hydrogen atoms (preferably twohydrogen atoms), and the foregoing groups optionally have a substituent.The examples and preferable ranges of this substituent are the same asthe examples and preferable ranges of the substituent which thecondensed ring-containing aromatic hydrocarbon optionally has.

In the polymer host material, the total content of the condensedring-containing aromatic hydrocarbon group and the group obtained byremoving from an aromatic hydrocarbon group, a heterocyclic group and anaromatic amine compound other than the condensed ring-containingaromatic hydrocarbon group one or more hydrogen atoms, contained in thepolymer compound, is usually 1% by mol to 100% by mol with respect tothe total content of all constitutional units contained in the polymercompound, and since the initial degradation of the light emitting deviceof the present embodiment is more suppressed, it is preferably 50% bymol to 100% by mol, and more preferably 70% by mol to 100% by mol.

The polymer host material may contain only one type of theconstitutional unit or may contain two or more types of theconstitutional units other than the condensed ring-containing aromatichydrocarbon group, in the polymer compound.

<Guest Material>

The aromatic amine compound denotes a compound containing a skeleton inwhich at least one of an amino group and a substituted amino group issubstituted in an aromatic hydrocarbon group or an aromatic heterocyclicgroup (hereinafter, referred to also as “aromatic amine skeleton”). Thearomatic amine skeleton is preferably a skeleton in which one or moresubstituted amino groups are substituted in an aromatic hydrocarbongroup or an aromatic heterocyclic group, more preferably a skeleton inwhich one or more substituted amino groups are substituted in anaromatic hydrocarbon group, since the initial degradation of the lightemitting device of the present embodiment is more suppressed.

The examples and preferable range of the substituted amino group in anaromatic amine compound are the same as the examples and preferablerange of the substituted amino group as the substituent which thecondensed ring-containing aromatic hydrocarbon optionally has.

The aromatic amine compound may contain only one type of the substitutedamino group or may contain two or more types of the substituted aminogroups, in the compound. Further, the aromatic amine compound maycontain only one of an amino group and a substituted amino group, or maycontain only one amino group and one substituted amino group, or maycontain two or more amino groups and two or more substituted aminogroups, in the compound.

The aromatic amine compound may contain only one type of the aromaticamine skeleton or may contain two or more types of the aromatic amineskeletons, in the compound. Further, the aromatic amine compound maycontain only one aromatic amine skeleton, or may contain two or morearomatic amine skeletons, in the compound.

In the aromatic amine skeleton, the number of amino groups substitutedon an aromatic hydrocarbon group or an aromatic heterocyclic group isusually from 0 to 10, preferably from 0 to 5, more preferably 0 to 3,and further preferably 0.

In the aromatic amine skeleton, the number of substituted amino groupssubstituted on an aromatic hydrocarbon group or an aromatic heterocyclicgroup is usually 1 to 10, and since the initial deterioration of thelight emitting device of this embodiment is more suppressed, the numberis preferably 1 to 7, more preferably 1 to 5, further preferably 1 to 3.

In the aromatic amine skeleton, the total number of an amino group and asubstituted amino group substituted on an aromatic hydrocarbon group oran aromatic heterocyclic group is usually 1 to 10, and since the initialdeterioration of the light emitting device of the present embodiment ismore suppressed, the total number is preferably 1 to 7, more preferably1 to 5, further preferably 1 to 3.

In the aromatic amine compound, the aromatic hydrocarbon group ispreferably a group obtained by removing from a mono-cyclic or bi-cyclicto hexa-cyclic aromatic hydrocarbon one or more hydrogen atoms bondingdirectly to carbon atoms constituting the ring, more preferably a groupobtained by removing from a tri-cyclic to penta-cyclic aromatichydrocarbon one or more hydrogen atoms bonding directly to carbon atomsconstituting the ring, further preferably a group obtained by removingfrom anthracene, phenanthrene, fluorene, benzoanthracene,benzophenanthrene, benzofluorene or pyrene one or more hydrogen atomsbonding directly to carbon atoms constituting the ring, particularlypreferably a group obtained by removing from benzoanthracene,benzophenanthrene or pyrene one or more hydrogen atoms bonding directlyto carbon atoms constituting the ring, since the initial degradation ofthe light emitting device of the present embodiment is more suppressed,and the foregoing groups optionally have a substituent.

In the aromatic amine compound, the aromatic heterocyclic groupincludes, for example, groups obtained by removing from a mono-cyclic orbi-cyclic to hepta-cyclic aromatic heterocyclic compound amongheterocyclic compounds exemplified in the section of the heterocyclicgroup described above one or more hydrogen atoms bonding directly toatoms constituting the ring, and is preferably a group obtained byremoving from a mono-cyclic or bi-cyclic to hexa-cyclic aromaticheterocyclic compound one or more hydrogen atoms bonding directly toatoms constituting the ring, more preferably a group obtained byremoving form a tri-cyclic to penta-cyclic aromatic heterocycliccompound one or more hydrogen atoms bonding directly to atomsconstituting the ring, further preferably a group obtained by removingfrom dibenzofuran, dibenzothiophene, carbazole, azaanthracene,diazaanthracene, azaphenanthrene, diazaphenanthrene, benzocarbazole,benzonaphthofuran or benzonaphthothiophene one or more hydrogen atomsbonding directly to atoms constituting the ring, and the foregoinggroups optionally have a substituent.

In the aromatic amine compound, the substituent which the aromatichydrocarbon group and the aromatic heterocyclic group optionally have isa substituent other than an amino group and a substituted amino group,and is preferably a halogen atom, an alkyl group, a cycloalkyl group, analkoxy group, a cycloalkoxy group, an aryl group or a monovalentheterocyclic group, more preferably an alkyl group, a cycloalkyl group,an aryl group or a monovalent heterocyclic group, further preferably analkyl group or a cycloalkyl group, and the foregoing groups optionallyfurther have a substituent.

In the aromatic amine compound, the examples and preferable ranges ofthe aryl group and the monovalent heterocyclic group as the substituentwhich an aromatic hydrocarbon group and an aromatic heterocyclic groupoptionally have are the same as the examples and preferable ranges ofthe aryl group and the monovalent heterocyclic group as the substituentwhich an aromatic hydrocarbon in which only three or more benzene ringsare condensed optionally has, respectively.

In the aromatic amine compound, the examples and preferable ranges ofthe substituent which the substituent which an aromatic hydrocarbongroup and an aromatic heterocyclic group optionally have optionallyfurther has are the same as the examples and preferable ranges of thesubstituent which the substituent which an aromatic hydrocarbon in whichonly three or more benzene rings are condensed optionally has optionallyfurther has.

The guest material may further contain a compound other than thearomatic amine compound, however, since the initial deterioration of thelight emitting device of this embodiment is more suppressed, it ispreferable that the guest material contains an aromatic amine compoundas the main component. The content ratio of the aromatic amine compoundin the guest material may be, for example, 10% by mass or more, andsince the initial deterioration of the light emitting device of thisembodiment is more suppressed, it is preferably 30% mass or more, morepreferably 50% by mass or more, further preferably 70% by mass or more,particularly preferably 90% by mass or more, especially preferably 95%by mass or more, and it may also be 100% by mass.

The guest material may contain only one type of the aromatic aminecompound or may contain two or more types of the aromatic aminecompounds. When the guest material further contains a compound otherthan the aromatic amine compound, the guest material may contain onlyone type or may contain two or more types of the compounds other thanthe aromatic amine compound.

The aromatic amine compound may be a polymer compound (hereinafter,referred to also as “polymer guest material”) or may be a low molecularcompound (hereinafter, referred to also as “low molecular guestmaterial”), and the low molecular quest material is preferable.

(Low Molecular Guest Material)

The molecular weight of the low molecular guest material is usually1×10² to 1×10⁴, preferably 2×10² to 5×10³, more preferably 3×10² to2×10³, and further preferably 4×10² to 1×10³.

The total number of amino groups and substituted amino groups containedin the low molecular guest material is usually 1 to 20, and since theinitial deterioration of the light emitting device of this embodiment ismore suppressed, the number is preferably 1 to 15, more preferably 1 to10, further preferably 1 to 5, and particularly preferably 1 to 3.

The total number of amino groups contained in the low molecular guestmaterial is usually 0 to 10, preferably 0 to 5, more preferably 0 to 3,and further preferably 0.

The total number of substituted amino groups contained in the lowmolecular guest material is usually 1 to 20, and since the initialdeterioration of the light emitting device of the present embodiment ismore suppressed, it is preferably 1 to 15, more preferably 1 to 10,further preferably 1 to 5, and particularly preferably 1 to 3.

The low molecular guest material may contain only one type of thesubstituted amino group or two or more types of the substituted aminogroups, however, since synthesis of the low molecular host material iseasy, one to ten types are preferable, one to five types are morepreferable, one to three types are further preferable, and one type isparticularly preferable.

The total number of aromatic amine skeletons contained in the lowmolecular guest material is usually from 1 to 10, and since the initialdeterioration of the light emitting device of this embodiment is moresuppressed, it is preferably from 1 to 7, more preferably 1 to 5,further preferably 1 to 3, and particularly preferably 1.

The low molecular guest material may contain only one type of thearomatic amine skeleton or two or more types of the aromatic amineskeletons, however, since synthesis of the low molecular host materialis easy, 1 to 5 types are preferable, 1 to 3 types are more preferable,and 1 type is further preferable.

[Compound Represented by the Formula (FB)]

The low molecular guest material is preferably a compound represented bythe formula (FB), since the initial degradation of the light emittingdevice of the present embodiment is more suppressed.

n^(1H) is usually an integer of 1 or more and 10 or less, and sincesynthesis of a compound represented by the formula (FB) is easy, it ispreferably an integer of 1 or more and 7 or less, more preferably aninteger of 1 or more and 5 or less, and further preferably an integer of1 or more and 3 or less.

Ar^(1B) is preferably an aromatic hydrocarbon group optionally having asubstituent, since the initial deterioration of the light emittingdevice of this embodiment is more suppressed.

The examples and preferable ranges of the aromatic hydrocarbon group andthe aromatic heterocyclic group for Ar^(1B) are the same as the examplesand preferable ranges of the aromatic hydrocarbon group and the aromaticheterocyclic group in the aromatic amine compound, respectively.

The examples and preferable ranges of the substituent which Ar^(1B)optionally has are the same as the examples and preferable ranges of thesubstituent which the aromatic hydrocarbon group and the aromaticheterocyclic group optionally have, in the aromatic amine compound.

R^(1B) is preferably a substituted amino group since the initialdeterioration of the light emitting device of the present embodiment ismore suppressed, and this group optionally further has a substituent.

The examples and preferable ranges of the substituted amino group forR^(1B) are the same as the examples and preferable ranges of thesubstituted amino group in the aromatic amine compound.

The examples and preferable ranges of the substituent which R^(1B)optionally has are the same as the examples and preferable ranges of thesubstituent which the substituent which the aromatic hydrocarbon groupand the aromatic heterocyclic group optionally have optionally furtherhas, in the aromatic amine compound.

Examples of the low molecular guest material include compoundsrepresented by the following formula and compounds described inExamples. These compounds optionally have a substituent. In the formula,Z¹ has the same meaning as described above.

(Polymer Guest Material)

The preferable ranges of the number average molecular weight and theweight average molecular weight in terms of polystyrene of the polymerguest material are the same as the preferable ranges of the numberaverage molecular weight and the weight average molecular weight interms of polystyrene of the polymer host material, respectively.

The polymer guest material may be any of a block copolymer, a randomcopolymer, an alternating copolymer and a graft copolymer, or may beanother form, and a copolymer obtained by copolymerizing a plurality ofraw material monomers is preferable.

The polymer guest material can be referred to as a polymer compoundcontaining a constitutional unit having an aromatic amine skeleton. Thepolymer guest material preferably contains an aromatic amine skeleton inthe main chain of the polymer compound, since the initial deteriorationof the light emitting device of this embodiment is more suppressed.

In the polymer guest material, the aromatic amine skeleton is preferablya group obtained by removing from a compound represented by the formula(FB) one or more hydrogen atoms (preferably five or less, morepreferably 1 to 3, further preferably 2 hydrogen atoms), since theinitial deterioration of the light emitting device of the presentembodiment is more suppressed.

In the polymer guest material, the content of the aromatic amineskeleton contained in the polymer compound is usually 0.1% by mol to100% by mol based on the total content of all constitutional unitscontained in the polymer compound, and since the initial deteriorationof the light emitting device of this embodiment is more suppressed, itis preferably 1% by mol to 100% by mol, more preferably 5% by mol to100% by mol, and further preferably 10% by mol to 100% by mol.

In the polymer guest material, the polymer compound may contain only onetype of the aromatic amine skeleton or may contain two or more types ofthe aromatic amine skeletons, and since synthesis of the polymer guestmaterial is easy, one to five types are preferable, one to three typesare more preferable, and one type is further preferable.

In the polymer guest material, the examples and preferable ranges of thesubstituent which the aromatic amine skeleton optionally has are thesame as the examples and preferable ranges of the substituent which thearomatic hydrocarbon group and the aromatic heterocyclic groupoptionally have, in the aromatic amine compound.

In the polymer guest material, the polymer compound may contain aconstitutional unit other than the aromatic amine skeleton, and it ispreferable that a constitutional unit other than the aromatic amineskeleton is contained in the main chain of the polymer compound.

Examples of the constitutional unit other than the aromatic amineskeleton include aromatic hydrocarbon groups (preferably an arylenegroup) and heterocyclic groups (preferably a divalent heterocyclicgroup), and the foregoing groups optionally have a substituent. Theexamples and preferable ranges of the substituent are the same as theexamples and preferable ranges of the substituent which the condensedring-containing aromatic hydrocarbon optionally has.

In the polymer guest material, the total content of the aromatic amineskeleton, the aromatic hydrocarbon group and the heterocyclic groupcontained in the polymer compound is usually 1% by mol to 100% by molbased on the total content of all the constitutional units contained inthe polymer compound, and since the initial deterioration of the lightemitting device of the present embodiment is more suppressed, it ispreferably 50% by mol to 100% by mol, and more preferably 70% by mol.100% by mol.

In the polymer guest material, the polymer compound may contain only onetype of the constitutional unit or may contain two or more types of theconstitutional units other than the aromatic amine skeleton.

<Amount (C¹) of Silicon Atom Contained in Guest Material>

In the composition for light emitting device of the present embodiment,the amount (C¹) of a silicon atom contained in the guest material isusually 750 ppm by mass or less based on the total amount of the guestmaterial. In the present specification, the phrase “the amount of asilicon atom contained in the guest material” does not mean that theguest material contains a silicon atom, and the guest material may ormay not contain a silicon atom. In the guest material of the presentembodiment, the amount of a silicon atom is preferably 75 ppm by mass orless, more preferably 7.5 ppm by mass or less, further preferably 5 ppmby mass or less, particularly preferably 3 ppm by mass or less,especially preferably 1 ppm by mass or less, particularly morepreferably 0.5 ppm by mass or less, especially more preferably 0.1 ppmby mass or less, especially particularly preferably 0 ppm by mass, sincethe initial deterioration of the light emitting device of thisembodiment is more suppressed.

The amount (C₁) of a silicon atom contained in the guest material of thepresent embodiment is such that when one type of the guest material ofthe present embodiment is used, the amount of a silicon atom in the onetype of the guest material is regarded as C¹, and when the guestmaterial of the present embodiment is composed of a plurality types ofcompounds having different amounts of a silicon atom, C¹ is calculatedaccording to the amounts of a silicon atom in the plurality types of thecompounds and the mass ratio of each compound. A specific method ofcalculating C¹ will be described using examples D1 and D2 describedlater.

First, in Example D1, the amount of a silicon atom in the compound EM2measured by ICP emission spectroscopy is below the detection limit,thus, C¹ is 0 ppm by mass.

Next, in Example D2, the amounts of a silicon atom in the compound EM1and the compound EM2 measured by ICP emission spectroscopy are 8 ppm bymass and below the detection limit (that is, 0 ppm by mass),respectively. The mass ratio between the compound EM1 and the compoundEM2 is compound EM1:compound EM2=3:7.

Therefore, C₁ in Example D2 can be determined from the amounts of asilicon atom contained in the compound EM2 and the compound EM2 and thecharging amounts thereof, and is determined as follows.

C ¹={8×3/(3+7)}+{0×7/(3+7)}=2.4 ppm by mass

In the same manner, C¹ in Example D3 is 0 ppm by mass.

<Amount (C^(H)) of Silicon Atom Contained in Host Material>

In the composition for light emitting device of the present embodiment,the amount (C^(H)) of a silicon atom contained in the host material isusually 2000 ppm by mass or less based on the total amount of the hostmaterial. In the present specification, the phrase “amount of a siliconatom contained in the host material” does not mean that the hostmaterial contains a silicon atom, and the host material may or may notcontain a silicon atom. In the host material of the present embodiment,the amount of a silicon atom is preferably 200 ppm by mass or less, morepreferably 20 ppm by mass or less, further preferably 10 ppm by mass orless, particularly preferably 5 ppm by mass or less, more particularlypreferably 1 ppm by mass or less, especially preferably 0.5 ppm by massor less, more especially preferably 0.1 ppm by mass or less, and stillparticularly preferably 0 ppm by mass, since the initial deteriorationof the light emitting device of the present embodiment is moresuppressed.

The specific calculation method of C^(H) can be obtained in the samemanner as the specific calculation method of C¹ described above.

For example, in Example D1, C^(H) is 0 ppm by mass. In Example D2, C^(H)is 0 ppm by mass. In Example D3, C^(H) is 0.53 ppm by mass.

<Method for reducing C¹ and C^(H)>

As a method for reducing C¹ and C^(H), for example, purification can bementioned.

The purification includes known purification methods described in the4th edition Experimental chemistry course (1993, Maruzen Co., Ltd.), the5th edition Experimental chemistry course (2007, Maruzen Co., Ltd.), Newexperimental chemistry course (1975, Maruzen Co., Ltd.), Guidance oforganic chemistry experiment (1988, Kagakudojin Publishing) and thelike.

Purification includes, for example, sublimation, extraction,reprecipitation, recrystallization, chromatography, and adsorption.

The purification of the low molecular quest material and the lowmolecular host material is preferably sublimation, recrystallization,chromatography or adsorption, more preferably sublimation orrecrystallization, further preferably sublimation, since the amount of asilicon atom can be further reduced.

The purification of the polymer guest material and the polymer hostmaterial is preferably reprecipitation, chromatography or adsorptionbecause the amount of a silicon atom can be further reduced.

When purification is performed twice or more, those methods may be thesame or different.

In sublimation, the degree of vacuum and the sublimation temperature maybe appropriately set according to the material to be sublimated. Thedegree of vacuum is preferably 1×10⁻¹⁰ Pa to 1×10⁵ Pa, more preferably1×10⁻⁷ Pa to 1×10² Pa, further preferably 1×10⁻⁵ Pa to 1 Pa, andparticularly preferably 1×10⁻⁴ Pa to 1×10⁻² Pa. Further, the sublimationtemperature is preferably −100° C. to 1000° C., more preferably 0° C. to700° C., further preferably 100° C. to 500° C., and particularlypreferably 200° C. to 350° C.

The extraction is preferably separating or solid-liquid extraction usinga Soxhlet extractor.

The solvent used for the extraction includes, for example, alcoholsolvents such as methanol, ethanol, propanol, ethylene glycol, glycerin,2-methoxyethanol, 2-ethoxyethanol and the like; ether solvents such asdiethyl ether, tetrahydrofuran (THF), dioxane, cyclopentyl methyl ether,diglyme and the like; halogen solvents such as methylene chloride,chloroform and the like; nitrile solvents such as acetonitrile,benzonitrile and the like; hydrocarbon solvents such as hexane, decalin,toluene, xylene, mesitylene and the like; amide solvents such asN,N-dimethylformamide, N,N-dimethylacetamide and the like; acetone,dimethyl sulfoxide, and water. The solvent may be used alone or incombination of two or more.

The chromatography is preferably column chromatography.

Silica gel or alumina is preferred as the filler used for columnchromatography.

Examples of solvents used for chromatography are the same as theexamples of solvents used for extraction.

Examples of the solvent used for reprecipitation and recrystallizationare the same as the examples of the solvent used for extraction.

As the adsorption, treatment with an adsorbent is preferable. Theadsorbent is preferably activated carbon, silica gel, alumina or Celite.

The treatment with the adsorbent is usually performed in a solvent.Examples of the solvent used for the treatment with the adsorbent arethe same as the examples of the solvent used for the extraction.

<Composition for Light Emitting Device>

The composition for light emitting device of the present embodimentcontains a host material and a quest material.

In the composition for light emitting device of the present embodiment,the host material and the quest material each may be contained singly orin combination of two or more, respectively.

In the composition for light emitting device of the present embodiment,the maximum peak wavelength of the emission spectrum of the hostmaterial at room temperature is preferably shorter than the maximum peakwavelength of the emission spectrum of the guest material at roomtemperature.

In the composition for light emitting device of this embodiment, themaximum peak wavelength of the emission spectrum of the host material atroom temperature is preferably 300 nm or more and 500 nm or less, morepreferably 330 nm or more and 480 nm or less, and further preferably 360nm or more and 460 nm or less.

In the composition for light emitting device of this embodiment, themaximum peak wavelength of the emission spectrum of the guest materialat room temperature is preferably 380 nm or more and 500 nm or less,more preferably 400 nm or more and 490 nm or less, and furtherpreferably 430 nm or more and 480 nm or less.

The maximum peak wavelength of the emission spectrum of the hostmaterial and the quest material can be evaluated by dissolving themeasurement object in an organic solvent such as xylene, toluene,chloroform or tetrahydrofuran to prepare a dilute solution (1×10⁻⁶% bymass to 1×10⁻³% by mass), and measuring the PL spectrum of the dilutedsolution at room temperature. As the organic solvent for dissolving themeasurement object, toluene or xylene is preferable.

In the composition for light emitting device of the present embodiment,the total amount of a silicon atom contained in the host material and asilicon atom contained in the guest material is 20 ppm by mass or lesswith respect to the total amount of the host material and the guestmaterial, and since the initial deterioration of the light emittingdevice of the embodiment is suppressed, it is preferably 18 ppm by massor less, more preferably 10 ppm by mass or less, further preferably 5ppm by mass or less, particularly preferably 3 ppm by mass or less,especially particularly preferably 1 ppm by mass or less, stillparticularly preferably 0.5 ppm by mass or less, still more particularlypreferably 0.1 ppm by mass or less, and particularly preferably 0 ppm bymass. In addition, the total amount of a silicon atom contained in thehost material and a silicon atom contained in the guest material, in thecomposition for light emitting device of the present embodiment, ispreferably 0.001 ppm by mass or more, more preferably 0.005 ppm by massor more, further preferably 0.01 ppm by mass or more, particularlypreferably 0.05 ppm by mass or more, especially preferably 0.1 ppm bymass or more, particularly preferably 0.2 ppm by mass or more,particularly further preferably 0.5 ppm by mass or more, and especiallyparticularly preferably 0.7 ppm by mass or more, with respect to thetotal amount of the host material and the guest material, since theinitial deterioration of the light emitting device of the presentembodiment can be controlled.

In the present embodiment, the reason why the initial deterioration ofthe light emitting device is suppressed is considered as follows.

The aromatic compound contained as a host material in the compositionfor light emitting device of this embodiment has a condensed ringskeleton in which only three or more benzene rings are condensed. Thepresent inventors believe that such a condensed ring skeletonelectrically interacts with an aromatic amine compound contained in theguest compound. On the other hand, the present inventors believe thatthe aromatic amine compound contained as a guest material in thecomposition for light emitting device of this embodiment electricallyinteracts with the aromatic compound contained as a host material. Then,the present inventors believe that, in the composition for lightemitting device of the present embodiment, when the total amount of asilicon atom contained in the host material and a silicon atom containedin the guest material exceeds a predetermined amount, a silicon atomexerts an adverse effect on the above-described interaction. Then, it isconsidered that this adverse effect causes a decrease in the lightemission characteristics, charge transport characteristics or chargeinjection characteristics of the composition for light emitting deviceof the present embodiment, or disrupts the balance of the charges of thelight emitting device of the present embodiment, leading to the initialdeterioration of the light emitting device of the present embodiment.

Hence, based on the above-described idea, the present inventors believethat, since the total amount of a silicon atom contained in the hostmaterial and a silicon atom contained in the guest material is in aspecific range, the effect by a silicon atom described above issuppressed, and the effect of suppressing the initial deterioration ofthe light emitting device is obtained, in the present embodiment.

The total amount (ppm by mass) of a silicon atom contained in the hostmaterial and a silicon atom contained in the guest material is expressedby C^(H)W^(H)+C¹W¹, the ratio of the mass of the host material to thetotal mass of the host material and the guest material being WEI and theratio of the mass of the guest material to the total mass of the hostmaterial and the guest material being W¹.

W^(H) is usually 0.01 to 0.9999, and since the initial deterioration ofthe light emitting device of this embodiment is more suppressed, it ispreferably 0.30 to 0.999, more preferably 0.50 to 0.995, furtherpreferably 0.70 to 0.99, and particularly preferably 0.85 to 0.95.

W¹ is usually 0.0001 to 0.99, and since the initial deterioration of thelight emitting device of the present embodiment is more suppressed, itis preferably 0.001 to 0.70, more preferably 0.005 to 0.50, furtherpreferably 0.01 to 0.30, and particularly preferably 0.05 to 0.15.

The specific method for calculating W^(H) and W¹ will be illustratedusing Example D1 and Example D2 described later.

First, in Example D1, the mass ratio of a compound H2 (host material)and a compound EM2 (guest material) is compound H2:compound EM2=90:10.

That is, W^(H) and W¹ in Example D1 can be determined from the chargingamounts, and determined as follows.

W ^(H)=90/(90+10)=0.90

W ¹=10/(90+10)=0.10

In Example D2, the mass ratio of a compound H2, compound EM1 and acompound EM2 is compound H2:compound EM1:compound EM2=90:3:7.

That is, W^(H) and W¹ in Example D2 can be determined from the chargingamounts, and determined as follows.

W ^(H)=90/(90+3+7)=0.90

W ¹=(3+7)/(90+3+7)=0.10

In the same manner, W^(H) and W¹ in Example D3 are determined asdescribed below.

W ^(H)=(2+88)/(2+88+10)=0.90

W ¹=10/(2+88+10)=0.10

As described above, C^(H)W^(H)+C¹W¹ can be calculated by calculating C¹,C^(H), W¹ and W^(H).

For example, C^(H)W^(H)+C¹W¹ in Example D1 is determined as describedbelow.

C ^(H) W ^(H) +C ¹ W ¹=(0×0.90)+(0×0.10)=0 ppm by mass

For example, C^(H)W^(H)+C¹W¹ in Example D2 is determined as follows.

C ^(H) W ^(H) +C ¹ W ¹=(0×0.90)+(2.4×0.10)=0.24 ppm by mass

For example, C^(H)W^(H)+C¹W¹ in Example D3 is determined as follows.

C ^(H) W ^(H) +C ¹ W ¹=(0.53×0.90)+(0×0.10)=0.48 ppm by mass

C^(H)W^(H)+C¹W¹ is usually 20 ppm by mass or less, and since the initialdegradation of the light emitting device of the present embodiment issuppressed, it is preferably 18 ppm by mass or less, more preferably 10ppm by mass or less, further preferably 5 ppm by mass or less,particularly preferably 3 ppm by mass or less, especially preferably 1ppm by mass or less, especially more preferably 0.5 ppm by mass or less,especially further preferably 0.1 ppm by mass or less, and especiallyparticularly preferably 0 ppm by mass. Further, C^(H)W^(H)+C¹W¹ ispreferably 0.001 ppm by mass or more, more preferably 0.005 ppm by massor more, further preferably 0.01 ppm by mass or more, particularlypreferably 0.05 ppm by mass or more, especially preferably 0.1 ppm bymass or more, especially more preferably 0.2 ppm by mass or more,especially further preferably 0.5 ppm by mass or more, and especiallyparticularly preferably 0.7 ppm by mass or more, since the initialdegradation of the light emitting device of the present embodiment canbe controlled.

(Other Component)

The composition for light emitting device of the present embodiment maybe a composition containing at least one material selected from thegroup consisting of a host material, a guest material, a holetransporting material, a hole injection material, an electrontransporting material, an electron injection material, a light emittingmaterial, an antioxidant, and a solvent. However, the hole transportingmaterial, the hole injection material, the electron transportingmaterial, the electron injection material, and the light emittingmaterial are different from the host material and the guest material.

When the composition for light emitting device of the present embodimentfurther contains at least one selected from the group consisting of ahole transporting material, a hole injection material, an electrontransporting material, an electron injection material, a light emittingmaterial, an antioxidant and a solvent, it is preferable to reduce theamount of a silicon atom contained therein by the above-describedpurification.

[Ink]

The composition containing the host material the quest material and asolvent (hereinafter, referred to as “ink”) is suitable for fabricationof a light emitting device using a wet method such as a spin coatingmethod, a casting method, a micro gravure coat method, a gravure coatmethod, a bar coating method, a roll coating method, a wire bar coatingmethod, a dip coating method, a spray coating method, a screen printingmethod, a Flexographic printing method, an offset printing method, aninkjet printing method, a capillary coating method, a nozzle coatingmethod and the like. The viscosity of the ink may be adjusted accordingto the type of the printing method, and is preferably 1 mPa·s to 20mPa·s at 25° C.

The solvent contained in the ink is preferably a solvent capable ofdissolving or uniformly dispersing solid components in the ink. Thesolvent includes, for example, chlorine solvents, ether solvents,aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, ketonesolvents, ester solvents, polyhydric alcohol solvents, alcohol solvents,sulfoxide solvents and amide solvents.

In the ink, the compounding amount of the solvent is usually 1000 to100000 parts by mass, when the sum of the host material and the guestmaterial is taken as 100 parts by mass.

The solvent may be used singly or in combination of two or more kindsthereof.

[Hole Transporting Material]

The hole transporting material is classified into a low molecularcompound and a polymer compound, and is preferably a polymer compoundhaving a crosslinkable group.

Examples of the polymer compound include polyvinyl carbazole andderivatives thereof; polyarylene having an aromatic amine structure in aside chain or a main chain and derivatives thereof. The polymer compoundmay be a compound to which an electron accepting site such as fullerene,tetrafluorotetracyanoquinodimethane, tetracyanoethylene, andtrinitrofluorenone is bonded.

In the composition for light emitting device of the present embodiment,when a hole transporting material is contained, the compounding amountof the hole transporting material is usually 1 part by mass to 400 partsby mass when the sum of the host material and the guest material istaken 100 parts by mass.

The transporting material may be used singly or in combination of two ormore.

[Electron Transporting Material]

The electron transporting material is classified into a low molecularcompound and a polymer compound. The electron transporting materialoptionally has a crosslinkable group.

The low molecular compound includes, for example, metal complex having8-hydroxyquinoline as a ligand, oxadiazole, anthraquinodimethane,benzoquinone, naphthoquinone, anthraquinone,tetracyanoanthraquinodimethane, fluorenone, diphenyldicyanoethylene anddiphenoquinone, and derivatives thereof.

The polymer compound includes, for example, polyphenylene, polyfluorene,and derivatives thereof. The polymer compound may be doped with a metal.

When the composition for light emitting device of the present embodimentcontains an electron transporting material, the compounding amount ofthe electron transporting material is usually 1 part by mass to 400parts by mass when the sum of the host material and the guest materialis taken as 100 parts by mass.

The electron transporting material may be used singly or in combinationof two or more.

[Hole Injection Material and Electron Injection Material]

The hole injection material and the electron injection material are eachclassified into a low molecular compound and a polymer compound. Thehole injection material and the electron injection material optionallyhave a crosslinkable group.

The low molecular compound includes, for example, metal phthalocyaninessuch as copper phthalocyanine and the like; carbon; oxides of metalssuch as molybdenum, tungsten and the like; metal fluorides such aslithium fluoride, sodium fluoride, cesium fluoride, potassium fluorideand the like.

The polymer compound includes, for example, polyaniline, polythiophene,polypyrrole, polyphenylenevinylene, polythienylenevinylene,polyquinoline and polyquinoxaline, and derivatives thereof; electricallyconductive polymers such as a polymer containing an aromatic aminestructure in the main chain or side chain, and the like.

When the hole-injection material and/or the electron-injection materialare contained in the composition for light emitting device of thepresent embodiment, the compounding amounts of the hole-injectionmaterial and the electron-injection material are usually 1 part by massto 400 parts by mass, respectively, when the sum of the host materialand the guest material is taken as 100 parts by mass.

The hole injection material and the electron injection material each maybe used alone or in combination of two or more.

(Ion Doping)

When the hole injection material or the electron injection materialcontains a conductive polymer, the electric conductivity of theconductive polymer is preferably 1×10⁻⁵ S/cm to 1×10³ S/cm. In order tomake the electric conductivity of the conductive polymer fall withinsuch a range, the conductive polymer can be doped with an appropriateamount of ions. The type of ions to be doped is an anion for a holeinjection material and a cation for an electron injection material.Examples of the anion include a polystyrene sulfonate ion, analkylbenzene sulfonate ion, and a camphor sulfonate ion. Examples of thecation include a lithium ion, a sodium ion, a potassium ion, and atetrabutylammonium ion.

The ions to be doped may be used singly or in combination of two ormore.

[Light Emitting Material]

The light emitting material is classified into a low molecular compoundand a polymer compound. The light emitting material optionally has acrosslinkable group.

The low molecular compound includes, for example, naphthalene andderivatives thereof, anthracene and derivatives thereof, perylene andderivatives thereof, and triplet light emitting complexes containingiridium, platinum or europium as the central metal.

The polymer compound includes polymer compounds containing, for example,an arylene group such as a phenylene group, a naphthalenediyl group, afluorenediyl group, a phenanthrenediyl group, a dihydrophenanthrenediylgroup, an anthracenediyl group, a pyrenediyl group and the like; anaromatic amine residue such as a group obtained by removing from anaromatic amine two hydrogen atoms, and the like; and a divalentheterocyclic group such as a carbazolediyl group, a phenoxazinediylgroup, a phenothiazinediyl group and the like.

In the case where the composition for light emitting device of thepresent embodiment contains a light emitting material, the content ofthe light emitting material is usually 0.1 part by mass to 400 parts bymass when the sum of the host material and the guest material is takenas 100 parts by mass.

The light emitting material may be used alone or in combination of twoor more.

[Antioxidant]

The antioxidant may be any compound that is soluble in the same solventas for the host material and the guest material and does not inhibitlight emission and charge transportation, and examples thereof include aphenolic antioxidant and a phosphorus-based antioxidant.

In the composition for light emitting device of the present embodiment,when an antioxidant is contained, the compounding amount of theantioxidant is usually 0.001 part by mass to 10 parts by mass when thesum of the host material and the guest material is taken as 100 parts bymass.

The antioxidant may be used alone or in combination of two or more.

<Film>

The film contains the composition for light emitting device of thepresent embodiment, and is suitable as a light emitting layer in a lightemitting device. The film can be formed by, for example, a wet methodusing an ink. In addition, the film can be produced by a dry method suchas a vacuum vapor deposition method. Examples of a method for forming afilm by a dry method include a method for vapor-depositing thecomposition for light emitting device of this embodiment and a methodfor co-evaporating a host material and a quest material.

The thickness of the film is usually from 1 nm to 10 μm.

<Light Emitting Device>

The light emitting device of the present embodiment contains thecomposition for light emitting device described above.

The configuration of the light emitting device of the present embodimentincludes, for example, an anode, a cathode, and an organic layercontaining the composition for light emitting device of the presentembodiment disposed between the anode and the cathode.

[Layer Constitution]

The layer containing the composition for light emitting device of thepresent embodiment is usually at least one layer selected from the groupconsisting of a light emitting layer, a hole transporting layer, a holeinjection layer, an electron transporting layer and an electroninjection layer. Preferably, it is a light emitting layer. These layerseach contain a light emitting material, a hole transporting material, ahole injection material, an electron transporting material, and anelectron injection material. Each of these layers can be formed using alight emitting material, a hole-transporting material, a hole injectionmaterial, an electron transporting material and an electron injectionmaterial by using the same method as for fabricating the above-describedfilm.

The light emitting device has a light emitting layer between an anodeand a cathode. The light emitting device of the present embodimentpreferably has at least one of a hole injection layer and a holetransporting layer between the anode and the light emitting layer fromthe standpoint of the hole injectability and the hole transportability,and preferably has at least one of an electron injection layer and anelectron transporting layer between the cathode and the light emittinglayer from the standpoint of the electron injectability and the electrontransportability.

The materials of the hole transporting layer, the electron transportinglayer, the light emitting layer, the hole injection layer and theelectron injection layer include the above-described hole transportingmaterials, electron transporting materials, light emitting materials,hole injection materials, electron injection materials and the like, inaddition to the composition for the light emitting device of the presentembodiment.

If the material for a hole transporting layer, the material for anelectron transporting layer and the material for a light emitting layerare soluble in solvents used in forming layers adjacent to the holetransporting layer, the electron transporting layer and the lightemitting layer in fabrication of a light emitting device, it ispreferable that the materials have a crosslinkable group to avoiddissolution of the materials in the solvents. By forming each layerusing the material having a crosslinkable group and cross-linking thecrosslinkable group, the layer can be insolubilized.

The method for forming each layer such as a light emitting layer, a holetransporting layer, an electron transporting layer, a hole injectionlayer, an electron injection layer and the like, in the light emittingdevice of the present embodiment, includes, for example, a dry methodsuch as vapor deposition from a powder and the like and a wet methodsuch as film formation from a solution or melted state when a lowmolecular compound is used, and for example, a wet method such as filmformation from a solution or melted state and the like when a polymercompound is used. The order, number and thickness of the layers to belaminated are adjusted in consideration of, for example, light emissionefficiency and initial deterioration.

[Substrate/Electrode]

The substrate in the light emitting device may advantageously be asubstrate on which an electrode can be formed and which does not changechemically in forming an organic layer, and is, for example, a substratemade of a material such as glass, plastic, silicon and the like. When anopaque substrate is used, it is preferable that the electrode farthestfrom the substrate is transparent or semi-transparent.

The material of the anode includes, for example, electrically conductivemetal oxides and semi-transparent metals, preferably includes indiumoxide, zinc oxide, tin oxide; electrically conductive compounds such asindium-tin-oxide (ITO), indium-zinc-oxide and the like;argentine-palladium-copper (APC) complex; NESA, gold, platinum, silverand copper.

The material of the cathode includes, for example, metals such aslithium, sodium, potassium, rubidium, cesium, beryllium, magnesium,calcium, strontium, barium, aluminum, zinc, indium and the like; alloyscomposed of two or more of them; alloys composed of at least one of themand at least one of silver, copper, manganese, titanium, cobalt, nickel,tungsten and tin; and graphite and graphite intercalation compounds. Thealloy includes, for example, a magnesium-silver alloy, amagnesium-indium alloy, a magnesium-aluminum alloy, an indium-silveralloy, a lithium-aluminum alloy, a lithium-magnesium alloy, alithium-indium alloy and a calcium-aluminum alloy.

Each of the anode and the cathode may take a laminated structurecomposed of two or more layers.

The light emitting device of the present embodiment can be suitably usedas a light source for backlight of a liquid crystal display device, alight source for illumination, an organic EL lighting, a display devicefor computers, televisions and portable terminals (for example, organicEL display and organic EL television).

Although suitable embodiments of the present invention are describedabove, the present invention is not limited to the above-mentionedembodiments.

For example, one aspect of the present invention may relate to a methodfor producing a composition for light emitting device in which a hostmaterial and a guest material are blended.

<Production Method (1)>

In one aspect, the method for producing a composition for light emittingdevice may be a production method of a composition for light emittingdevice, including a host material preparation step of preparing a hostmaterial containing a condensed ring-containing aromatic compound, aguest material preparation step of preparing a guest material containingan aromatic amine compound, and a production step of mixing the hostmaterial and the guest material at a compounding ratio by which thetotal amount of a silicon atom contained in the host material and asilicon atom contained in the guest material is 20 ppm by mass or less,to obtain a composition for light emitting device (hereinafter, alsoreferred to as “production method (1)”).

In the production method (1), the host material preparation step mayinclude a step (A-1) of preparing a condensed ring-containing aromaticcompound containing a silicon atom mixed therein and a step (A-2) ofpurifying at least a part of the condensed ring-containing aromaticcompound prepared in the step (A-1) to remove at least a part of thesilicon atom.

The content of a silicon atom in the condensed ring-containing aromaticcompound prepared in the step (A-1) is not particularly limited, and maybe, for example, 20 ppm by mass or more, may be 24 ppm by mass or more,may be 50 ppm by mass or more, may be 100 ppm by mass or more, may be500 ppm by mass or more, may be 1000 ppm by mass or more, may be 5000ppm by mass or more, may be 10,000 ppm by mass or more. The upper limitof the content of a silicon atom in the condensed ring-containingaromatic compound prepared in the step (A-1) is not particularlylimited, and the content may be, for example, 500,000 ppm by mass orless, may be 100,000 mass ppb or less, may be 50,000 ppm by mass orless.

The purification method in the step (A-2) includes the methodsexemplified in the above <Method for reducing C¹ and C^(H)>.

The content of a silicon atom in the condensed ring-containing aromaticcompound after the step (A-2) is usually 2,000 ppm by mass or less, andsince the initial deterioration of the light emitting device of thepresent embodiment is more suppressed, it is preferably 200 ppm by massor less, more preferably 20 ppm by mass or less, further preferably 10ppm by mass or less, particularly preferably 5 ppm by mass or less,especially particularly preferably 1 ppm by mass or less, particularlymore preferably 0.5 ppm by mass or less, still particularly preferably0.1 ppm by mass or less, and particularly preferably 0 ppm by mass.

The guest material preparation step may include a preparing step (B-1)of preparing an aromatic amine compound containing a silicon atom mixedtherein, and a step (B-2) of purifying at least a part of the aromaticamine compound prepared in the step (B-1) to remove at least a part ofthe silicon atom.

The content of a silicon atom in the aromatic amine compound prepared instep (B-1) is not particularly limited, and may be, for example, 7.5 ppmby mass or more, may be S ppm by mass or more, may be 20 ppm by mass ormore, may be 50 ppm by mass or more, may be 100 ppm by mass or more, maybe 500 ppm by mass or more, may be 1000 ppm by mass or more, may be 5000ppm by mass or more, and may be 10,000 ppm by mass or more. The upperlimit of the content of a silicon atom in the aromatic amine compoundprepared in the step (B-1) is not particularly limited, and the contentmay be, for example, 500000 ppm by mass or less, may be 100000 mass ppbor less, and may be 50,000 ppm by mass or less.

The purification method in the step (B-2) includes the methodsexemplified in the above <Method for reducing C¹ and C^(H)>.

The content of a silicon atom in the aromatic amine compound after thestep (B-2) is usually 750 ppm by mass or less, and since the initialdeterioration of the light emitting device of the present embodiment ismore suppressed, it is preferably 75 ppm by mass or less, morepreferably 7.5 ppm by mass or less, further preferably 5 ppm by mass orless, particularly preferably 3 ppm by mass or less, particularlypreferably 1 ppm by mass or less, particularly more preferably 0.5 ppmby mass or less, still Particularly preferably 0.1 ppm by mass or less,and particularly preferably 0 ppm by mass.

In the production method (1), in consideration of the amount of asilicon atom contained in the host material and the amount of a siliconatom contained in the guest material, the host material and the guestmaterial are mixed at a compounding ratio at which the sum of them is 20ppm by mass or less, in the production method. By this, a compositionfor light emitting device that can suppress the initial deterioration ofthe light emitting device can be obtained.

In the production step of the production method (1), the method ofmixing the host material and the guest material is not particularlylimited and includes, for example, a method in which the host materialand the guest material are dissolved in the solvent described in theabove-described ink section and mixed, a method of mixing the hostmaterial and the guest material in a solid state, a method of mixing thehost material and the guest material by co-vapor deposition, and thelike.

The production method (1) may further include a host materialmeasurement step of measuring the content of a silicon atom contained inthe condensed ring-containing aromatic compound. The production method(1) may further include a guest material measurement step of measuringthe content of a silicon atom contained in the aromatic amine compound.It is preferable that the production method (1) includes a host materialmeasurement step and a guest material measurement step. In the hostmaterial measurement step and the guest material measurement step, themethod of measuring the content of a silicon atom is preferably anICP/MS method.

In the production method (1), the host material measurement step and theguest material measurement step are preferably performed before theproduction step.

In the production method (1), the host material preparation steppreferably includes a host material measurement step. In the productionmethod (1), the guest material preparation step preferably includes aguest material measurement step.

<Production Method (2)>

In another aspect, the method for producing a composition for lightemitting device may be a production method of a composition for lightemitting device including a host material preparation step of preparinga host material containing a condensed ring-containing aromaticcompound, a determination step of determining the compounding ratio ofthe guest material with respect to the host material, a guest materialpreparation step of preparing a guest material containing an aromaticamine compound and in which, when mixed with the host material at theabove-described compounding ratio, the total amount of a silicon atomcontained in the host material and a silicon atom contained in the guestmaterial with respect to the total amount of the host material and theguest material is 20 ppm by mass or less, and a production step ofmixing the host material and the guest material at the above-describedcompounding ratio, to obtain a composition for light emitting device(hereinafter, also referred to as “Production method (2)”).

In the production method (2), the host material preparation step mayinclude a step (A-1) of preparing a condensed ring-containing aromaticcompound containing a silicon atom mixed therein and a step (A-2) ofpurifying at least a part of the condensed ring-containing aromaticcompound prepared in the step (A-1) to remove at least a part of thesilicon atom. The steps (A-1) and (A-2) in the production method (2) maybe the same as the steps (A-1) and (A-2) in the above-describedproduction method (1).

In the production method (2), the compounding ratio may be determinedaccording to the characteristics of the light emitting device and thelike, in the determination step. In the determination step, for example,the compounding ratio may be determined based on the result of producinga light emitting device using a test composition using materials similarto the host material and the guest material described above, or thecompounding ratio may be determined based on the result of producing alight emitting device using a test composition in which the content of asilicon atom is over 20 ppm by mass.

In the production method (2), the content of a silicon atom allowable inthe guest material is determined, in the guest material preparationstep, depending on the content of a silicon atom in the host materialprepared in the host material preparation step and the compounding ratiodetermined in the determination step. That is, the guest materialpreparation step can be called a step of preparing a guest material inwhich the content of a silicon atom is within the allowable range.

In the production method (2), the guest material preparation step mayinclude, for example, a preparation step (B-1) of preparing an aromaticamine compound containing a silicon atom mixed therein, and a step (B-2)of purifying at least a part the aromatic amine compound prepared in thestep (B-1) to remove at least a part of the silicon atom. The steps(B-1) and (B-2) in the production method (2) may be the same as thesteps (B-1) and (B-2) in the above-described production method (1).

In the production method (2), the host material prepared in the hostmaterial preparation step and the guest material prepared in the guestmaterial preparation step are mixed at the compounding ratio determinedin the determination step, in the production step. By this, acomposition for light emitting device that can suppress the initialdeterioration of the light emitting device can be obtained.

The method of mixing the host material and the guest material in theproduction step of the production method (2) may be the same as themethod of mixing the host material and the guest material in theproduction step of the production method (1).

The production method (2) may further include the above-described hostmaterial measurement step. The production method (2) may further includethe above-described guest material measurement step. It is preferablethat the production method (2) includes the above-described hostmaterial measurement step and the above-described guest materialmeasurement step.

In the production method (2), the above-described host materialmeasurement step and the above-described guest material measurement stepare preferably performed before the production step.

In the production method (2), the host material preparation steppreferably includes the above-described host material measurement step.In the production method (2), the guest material preparation steppreferably includes the above-described guest material measurement step.

<Production Method (3)>

In still another aspect, the method for producing a composition forlight emitting device may be a production method of a composition forlight emitting device including a guest material preparation step ofpreparing a guest material containing an aromatic amine compound, adetermination step of determining the compounding ratio of the hostmaterial with respect to the guest material, a host material preparationstep of preparing a host material containing a condensed ring-containingaromatic compound and in which, when mixed with the guest material atthe above-described compounding ratio, the total amount of a siliconatom contained in the host material and a silicon atom contained in theguest material with respect to the total amount of the host material andthe guest material is 20 ppm by mass or less, and a production step ofmixing the guest material and the host material at the above-describedcompounding ratio, to obtain a composition for light emitting device(hereinafter, also referred to as “production method (3)”).

In the production method (3), the guest material preparation step mayinclude a step (B-1) of preparing an aromatic amine compound containinga silicon atom mixed therein, and a step (B-2) of purifying at least apart of the aromatic amine compound prepared in the step (B-1) to removeat least a part of the silicon atom. The steps (B-1) and (B-2) in theproduction method (3) may be the same as the steps (B-1) and (B-2) inthe above-described production method (1).

In the production method (3), the compounding ratio may be determinedaccording to the characteristics of the light emitting device, in thedetermination step. In the determination step, for example, thecompounding ratio may be determined based on the result of producing alight emitting device using a test composition using materials similarto the host material and the guest material described above, or thecompounding ratio may be determined based on the result of producing alight emitting device using a test composition in which the content of asilicon atom is over 20 ppm by mass.

In the production method (3), the content of a silicon atom allowable inthe host material is determined, in the host material preparation step,depending on the content of a silicon atom in the guest materialprepared in the guest material preparation step and the compoundingratio determined in the determination step. That is, the host materialpreparation step can be called a step of preparing a host material inwhich the content of a silicon atom is within the allowable range.

In the production method (3), the host material preparation step mayinclude, for example, a preparing step (A-1) of preparing a condensedring-containing aromatic compound containing a silicon atom mixedtherein, and a step (A-2) of purifying at least a part of the condensedring-containing aromatic compound prepared in the step (A-1) to removeat least a part of the silicon atom. The steps (A-1) and (A-2) in theproduction method (3) may be the same as the steps (A-1) and (A-2) inthe above-mentioned production method (1).

In the production method (3), the guest material prepared in the guestmaterial preparation step and the host material prepared in the hostmaterial preparation step are mixed at the compounding ratio determinedin the determination step, in the production step. By this, acomposition for light emitting device that can suppress the initialdeterioration of the light emitting device can be obtained.

The method of mixing the host material and the guest material in theproduction step of the production method (3) may be the same as themethod of mixing the host material and the guest material in theproduction step of the production method (1).

The production method (3) may further include the above-described hostmaterial measurement step. The production method (3) may further includethe above-described guest material measurement step. It is preferablethat the production method (3) includes the above-described hostmaterial measurement step and the above-described guest materialmeasurement step.

In the production method (3), the above-described host materialmeasurement step and the above-described guest material measurement stepare preferably performed before the production step.

In the production method (3), the host material preparation steppreferably includes the above-described host material measurement step.In the production method (3), the guest material preparation steppreferably includes the above-described guest material measurement step.

<Production Method (4)>

In still another aspect, the method of producing a composition for lightemitting device may be a production method of a composition for lightemitting device including a host material preparation step of preparinga condensed ring-containing aromatic compound as the host material, aguest material preparation step of preparing an aromatic amine compoundas the guest material, a determination step of determining thecompounding ratio of the host material and the guest material, apurification step of purifying at least a part of the condensedring-containing aromatic compound and the aromatic amine compound sothat, when the host material and the guest material are mixed at theabove-described compounding ratio, the total amount of a silicon atomcontained in the host material and a silicon atom contained in the guestmaterial with respect to the total amount of the host material and theguest material is 20 ppm by mass or less, and a production step ofmixing the host material containing the condensed ring-containingaromatic compound and the guest material containing the aromatic aminecompound, to obtain a composition for light emitting device(hereinafter, also referred to as “Production method (4)”).

In the production method (4), a silicon atom may be mixed in at leastone of the condensed ring-containing aromatic compound prepared in thehost material preparation step and the aromatic amine compound preparedin the guest material preparation step. That is, the host materialpreparation step may be a step of preparing a condensed ring-containingaromatic compound in which a silicon atom is mixed, or the guestmaterial preparation step may be a step of preparing an aromatic aminecompound in which a silicon atom is mixed.

In the production method (4), the compounding ratio may be determinedaccording to the characteristics of the light emitting device, in thedetermination step. In the determination step, for example, thecompounding ratio may be determined based on the result of producing alight emitting device using a test composition using materials similarto the host material and the guest material described above, thecompounding ratio may be determined based on the result of producing alight emitting device using a test composition in which the content of asilicon atom is over 20 ppm by mass, or the compounding ratio may bedetermined based on the result of producing a light emitting device witha test composition obtained by mixing the condensed ring-containingaromatic compound and the aromatic amine compound prepared in the hostmaterial preparation step and the guest material preparation step.

In the production method (4), at least a part of the condensedring-containing aromatic compound and the aromatic amine compound arepurified, in the purification step. The purification method includes themethods exemplified in the above <Method for Reducing C¹ and C^(H)>. Thepurification step may be a step of purifying only one of the condensedring-containing aromatic compound and the aromatic amine compound, ormay be a step of purifying both the condensed ring-containing aromaticcompound and the aromatic amine compound.

In the production method (4), the condensed ring-containing aromaticcompound and the aromatic amine compound are mixed at the compoundingratio determined in the determination step, in the production step. Atthis time, since the purification step has been performed, the totalamount of a silicon atom contained in the host material and a siliconatom contained in the guest material with respect to the total amount ofthe host material and the guest material is 20 ppm by mass or less. Bythis, a composition for light emitting device that can suppress theinitial deterioration of the light emitting device can be obtained.

The method of mixing the host material and the guest material in theproduction step of the production method (4) may be the same as themethod of mixing the host material and the guest material in theproduction step of the production method (1).

The production method (4) may further include the above-described hostmaterial measurement step. The production method (4) may further includethe above-described guest material measurement step. It is preferablethat the production method (4) includes the above-described hostmaterial measurement step and the above-described quest materialmeasurement step.

In the production method (4), the above-described host materialmeasurement step and the above-described guest material measurement stepare preferably performed before the production step.

In the production method (4), the host material preparation step or thepurification step preferably includes the above-described host materialmeasurement step. In the production method (2), the guest materialpreparation step or the purification step preferably includes theabove-described guest material measurement step.

Another aspect of the present invention relates to a method of producinga light emitting device. This production method may be a method ofproducing a light emitting device containing an anode, a cathode, and anorganic layer disposed between the anode and the cathode, including astep of forming the organic layer from the composition for lightemitting device produced by any of the above-described productionmethods (1) to (4)

In the method of producing a light emitting device of the presentembodiment, as a method for forming an organic layer, for example, theorganic layer can be formed using the same method as for producing afilm described above.

Further, in the method of producing a light emitting device of thepresent embodiment, the production method described in theabove-described section <Light emitting device> may be used.

In addition, as the light emitting device in the method of producing alight emitting device of the present embodiment, for example, the lightemitting device described in the above-described section <Light emittingdevice> is mentioned.

Examples

The present invention will be illustrated further in detail by examplesbelow, but the present invention is not limited to these examples.

In the present examples, the maximum peak wavelength of the emissionspectrum of the compound was measured by a spectrophotometer(manufactured by JASCO Corporation, FP-6500) at room temperature. Thecompound was dissolved in xylene at a concentration of about 0.8×10⁻⁴%by mass to prepare a xylene solution which was then used as a sample. Asthe excitation light, UV light having a wavelength of 325 nm was used.

In the present examples, the amount of a silicon atom contained in thecompound was measured by an ICP emission spectroscopic analysis method.

<Compound H1 and Compound EM1>

A compound H1 was synthesized with reference to a method described inJapanese Unexamined Patent Application Publication (JP-A) No.2011-105643.

A compound EM1 was synthesized with reference to a method described inInternational Publication WO 2011/137922.

The HPLC area percentage value of the compound H1 was 99.5% or more. Theamount (C^(H)) of a silicon atom contained in the compound H1 was 24 ppmby mass.

The HPLC area percentage value of the compound EM1 was 99.5% or more.The amount (C¹) of a silicon atom contained in the compound EM1 was 8ppm by mass.

<Purification of Compound H1 (Synthesis of Compound H2)>

A compound H2 was obtained by repeating sublimation purification of thecompound H1 until the amount of a silicon atom contained in the compoundH1 reached below the detection limit (0 ppm by mass). In sublimationpurification, the degree of vacuum was set to 3×10⁻³ Pa to 5×10⁻³ Pa,and the sublimation temperature was set to 250° C. to 300° C.

The HPLC area percentage value of the compound H2 was 99.5% or more. Theamount (C^(H)) of a silicon atom contained in the compound H2 was belowthe detection limit (0 ppm by mass).

<Purification of Compound EM1 (Synthesis of Compound EM2)>

A compound EM2 was obtained by repeating sublimation purification of thecompound EM until the amount of a silicon atom contained in the compoundEM1 reached below the detection limit (0 ppm by mass). In sublimationpurification, the degree of vacuum was set to 3×10⁻³ Pa to 5×10⁻Pa, andthe sublimation temperature was set to 250° C. to 300° C.

The HPLC area percentage value of the compound EM2 was 99.5% or more.The amount (C¹) of a silicon atom contained in the compound EM2 wasbelow the detection limit (0 ppm by mass).

The maximum peak wavelength of the emission spectrum of the compounds H1and H2 was 421 nm. The maximum peak wavelength of the emission spectrumof the compounds EM1 and EM2 was 454 nm.

<Example D1> Fabrication and Evaluation of Light Emitting Device D1(Formation of Anode and Hole Injection Layer)

An ITO film was attached with a thickness of 45 nm onto a glasssubstrate by a sputtering method, to form an anode. On the anode,ND-3202 (manufactured by Nissan Chemical Corporation) as a holeinjection material was spin-coated, to form a film with a thickness of35 nm. The substrate carrying the hole injection layer laminated thereonwas placed under an air atmosphere, and heated on a hot plate at 50° C.for 3 minutes, and further, heated at 230° C. for 15 minutes, to form ahole injection layer.

(Formation of Hole Transporting Layer)

The polymer compound HTL-1 was dissolved at a concentration of 0.7% bymass in xylene. The resultant xylene solution was spin-coated on thehole injection layer form a film with a thickness of 20 nm, and the filmwas heated on a hot plate at 180° C. for 60 minutes under a nitrogen gasatmosphere, to form a hole transporting layer. The polymer compoundHTL-1 is a polymer compound in Polymer Example 1 of InternationalPublication WO2014/102543.

(Formation of Light Emitting Layer)

The compound H2 and the compound EM2 (compound H2/compound EM2=90% bymass/10% by mass) were dissolved at a concentration of 2% by mass intoluene. The resultant toluene solution was spin-coated on the holetransporting layer to form a film with a thickness of 60 nm, and thefilm was heated at 130° C. for 10 minutes under a nitrogen gasatmosphere, to form a light emitting layer.

(Formation of Cathode)

The substrate carrying the light emitting layer formed thereon wasplaced in a vapor deposition machine, and the pressure in the machinewas reduced to 1.0×10⁻⁴ Pa or less, then, as cathode, sodium fluoridewas vapor-deposited with a thickness of about 4 nm on the light emittinglayer, then, aluminum was vapor-deposited with a thickness of about 80nm on the sodium fluoride layer. After vapor deposition, sealing with aglass substrate was performed, to fabricated a light emitting device D1.

(Evaluation of Light Emitting Device)

Voltage was applied to the light emitting device D1, to observe ELemission. The device was driven at constant current at 150 mA/cm², andthe time until the luminance reached 95% (hereinafter, referred to alsoas “LT95”) was measured.

Examples D2 to D6 and Comparative Example CD1

Fabrication and Evaluation of Light Emitting Devices D2 to D6 and CD1

Light emitting devices D2 to D6 and CD1 were fabricated in the samemanner as in Example D1, except that materials described in Table 1 wereused at the material ratios described in Table 1 instead of “compound H2and compound EM2 (compound H2/compound EM2=90% by mass/10% by mass)” in(Formation of light emitting layer) of Example D1.

Voltage was applied to the light emitting devices D2 to D6 and CD1, toobserve EL emission. LT95 of the light emitting devices D2 to D6 and CD1was measured.

The results of Examples D1 to D6 and Comparative Example CD1 are shownin Table 1. The relative values of LT95 of the light emitting devices D1to D6 when LT95 of the light emitting device CD1 is set to 1.0 areshown.

TABLE 1 light emitting layer material C^(H) C¹ C^(H)W^(H) + light ratio(ppm (ppm C¹W¹ LT95 emitting (% by by by (ppm by (relative devicematerial mass) mass) mass) mass) value) Example D1 D1 H2/EM2 90/10 0 0 02.7 Example D2 D2 H2/EM2/EM1 90/7/3 0 2.4 0.24 2.0 Example D3 D3H2/H1/EM2 88/2/10 0.53 0 0.48 2.0 Example D4 D4 H2/EM2/EM1 90/1/9 0 7.20.72 1.6 Example D5 D5 H2/H1/EM2 72/18/10 4.8 0 4.3 1.7 Example D6 D6H2/H1/EM2 18/72/10 19.2 0 17.3 1.3 Comparative CD1 H1/EM1 90/10 24 822.4 1.0 Example CD1

INDUSTRIAL APPLICABILITY

According to this invention, a composition which is useful forproduction of a light emitting device in which the initial deteriorationis suppressed is provided. The present invention is industrially usefulbecause the production of a light emitting device in which initialdeterioration is suppressed has effects such as resource saving, energysaving and the like.

1-7. (canceled)
 8. A method of producing a composition for lightemitting device containing a host material and a guest material blended,comprising a host material preparation step of preparing a host materialcontaining an aromatic compound having a condensed ring skeleton inwhich only three or more benzene rings are condensed, a guest materialpreparation step of preparing a guest material containing an aromaticamine compound, and a production step of mixing said host material andsaid guest material at a compounding ratio by which the total amount ofa silicon atom contained in said host material and a silicon atomcontained in said guest material is 20 ppm by mass or less, to obtain acomposition for light emitting device.
 9. The production methodaccording to claim 8, wherein said guest material preparation stepcomprises a preparation step (B-1) of preparing said aromatic aminecompound containing a silicon atom mixed therein, and a step (B-2) ofpurifying at least a part of said aromatic amine compound prepared insaid step (B-1) to remove at least a part of said silicon atom.
 10. Theproduction method according to claim 8, wherein said host materialpreparation step comprises a step (A-1) of preparing said aromaticcompound containing a silicon atom mixed therein, and a step (A-2) ofpurifying at least a part of said aromatic compound prepared in saidstep (A-1) to remove at least a part of said silicon compound.
 11. Amethod of producing a composition for light emitting device containing ahost material and a guest material blended, comprising a host materialpreparation step of preparing a host material containing an aromaticcompound having a condensed ring skeleton in which only three or morebenzene rings are condensed, a determination step of determining thecompounding ratio of said guest material with respect to said hostmaterial, a guest material preparation step of preparing a guestmaterial containing an aromatic amine compound and in which, when mixedwith said host material at said compounding ratio, the total amount of asilicon atom contained in said host material and a silicon atomcontained in said guest material with respect to the total amount ofsaid host material and said guest material is 20 ppm by mass or less,and a production step of mixing said host material and said guestmaterial at said compounding ratio to obtain a composition for lightemitting device.
 12. A method of producing a composition for lightemitting device containing a host material and a guest material blended,comprising a guest material preparation step of preparing a guestmaterial containing an aromatic amine compound, a determination step ofdetermining the compounding ratio of said host material with respect tosaid guest material, a host material preparation step of preparing ahost material containing an aromatic compound having a condensed ringskeleton in which only three or more benzene rings are condensed and inwhich, when mixed with said guest material at said compounding ratio,the total amount of a silicon atom contained in said host material and asilicon atom contained in said guest material with respect to the totalamount of said host material and said guest material is 20 ppm by massor less, and a production step of mixing said guest material and saidhost material at said compounding ratio, to obtain a composition forlight emitting device.
 13. A method of producing a composition for lightemitting device containing a host material and a guest material blended,comprising a host material preparation step of preparing an aromaticcompound having a condensed ring skeleton in which only three or morebenzene rings are condensed as the host material, a guest materialpreparation step of preparing an aromatic amine compound as the guestmaterial, a determination step of determining the compounding ratio ofsaid host material and said guest material, a purification step ofpurifying at least a part of said aromatic compound and said aromaticamine compound so that, when said host material and said guest materialare mixed at said compounding ratio, the total amount of a silicon atomcontained in said host material and a silicon atom contained in saidguest material with respect to the total amount of said host materialand said guest material is 20 ppm by mass or less, and a production stepof mixing said host material containing said aromatic compound and saidguest material containing said aromatic amine compound, to obtain acomposition for light emitting device.
 14. The production methodaccording to claim 8, further comprising a host material measurementstep of measuring the content of a silicon atom contained in saidaromatic compound, and a guest material measurement step of measuringthe content of a silicon atom contained in said aromatic amine compound.15. A method of producing a light emitting device containing an anode, acathode and an organic layer disposed between said anode and saidcathode, comprising a step of forming said organic layer from acomposition for light emitting device produced by the production methodaccording to claim 8.